Received: 21 May 2016 Revised: 28 February 2018 Accepted: 11 April 2018 DOI: 10.1111/jfr3.12451 ORIGINAL ARTICLE Aligning ancient and modern approaches to sustainable urban water management in China: Ningbo as a “Blue-Green City” in the “Sponge City” campaign Y-T. Tang1 | F.K.S. Chan1 | E.C. O'Donnell2 | J. Griffiths3 | L. Lau1 | D.L. Higgitt4 | C.R. Thorne2 1School of Geographical Sciences, University of Nottingham Ningbo, Ningbo, China Modern urban flood and water management emphasises holistic strategies that 2School of Geography, University of Nottingham, reduce flood risk while providing cobenefits to urban economies, societies, and Nottingham, UK environments. The “Blue-Green City” concept provides a viable framework for 3National Institute for Water and Atmospheric putting this into practice. Ningbo, is a coastal city with high flood risk, whose his- Research, Christchurch, New Zealand tory as a Chinese “water town” demonstrates that approaches to water management 4 Lancaster University College, Beijing Jiaotong implicit to the “Blue-Green” concept were practiced in ancient times, and lessons University, Weihai, China can be learned from these applications. Furthermore, recent launch of the “Sponge Correspondence ” Prof. Colin R. Thorne, School of Geography, City campaign by China's National Government demonstrates the political will to University of Nottingham, University Park, implement sustainable flood and water management in ways consistent with the Nottingham, NG7 2RD, UK. “Blue-Green” ideals. Selection of Ningbo for a pilot project presents the opportu- Email: [email protected] nity to integrate new “Sponge city” approaches with ancient “Blue-Green” princi- Funding information UK Engineering and Physical Sciences Research ples, within the contexts of both new urban development and retrofit. Reinventing Council (EPSRC), Grant/Award Numbers: EP/ traditional approaches to urban water management and governance offers the possi- K013661/1, EP/P004180/1, EP/N008103/1; bility of maintaining flood risk at acceptable levels without constraining urban Environment Agency and Rivers Agency growth in China and other countries experiencing rapid urban development. (Northern Ireland); Sandpit Fund offered by UNNC KEYWORDS Blue-Green Cities, integrated flood risk management, Sponge Cities, integrated water management, sustainable drainage systems, water-sensitive urban design 1 | INTRODUCTION infrastructure (BGI) and Water Sensitive Urban Design (WSUD) are recognised as mechanisms to integrate the 1.1 | Overview water cycle with urban development while helping meet ongoing challenges of climate change and rapid urban Flooding can be a catastrophic natural hazard and mitigating growth (Ashley et al., 2013; Novotny et al., 2010; Wong & flood losses is a priority for disaster risk reduction (UNISDR, 2015). In recent decades, approaches to flood Brown, 2009). Innovative approaches to flood and water management management in developed countries have evolved from pre- vention to risk management, employing holistic approaches are also gaining momentum in developing countries, includ- that provide a range of cobenefits through, for example, ing China (e.g., Zhang et al., 2016), though the need for water quality improvement, restoration of river ecology, and location-specific adaptations related to regional variabilities enhanced recreational opportunities, in addition to reducing in climate, demographics, and the stage of development flood risk (Downs & Thorne, 2000; Jha, Bloch, & Lamond, must be taken into account (Higgitt, 2015). It follows that 2012). Sustainable Drainage Systems (SuDS), “Blue-Green” the first step in updating national Chinese water management This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2018 The Authors. Journal of Flood Risk Management published by Chartered Institution of Water and Environmental Management and John Wiley & Sons Ltd. J Flood Risk Management. 2018;e12451. wileyonlinelibrary.com/journal/jfr3 1of14 https://doi.org/10.1111/jfr3.12451 2of14 TANG ET AL. TABLE 1 Comparison between Blue-Green and Grey infrastructure on various functions Blue-Green infrastructure Grey infrastructure Concept of design Creating landscape mimicking natural water Creating sizable channel and drainage systems cycle in urban environment (O'Donnell, to direct excessive precipitation or surface Lamond, & Thorne, 2018) flow from urban areas in a short period of time (Fleming, 2002). Flood control Reducing peak flow during small or mild Discharge designed amount of excessive flow floods (Guan, Ahilan, Yu, Peng, & Wright, in short period of time (Hutter, 2007; 2018; Haghighatafshar et al., 2018) Schanze, 2006) Sediment control Creating a heathy balance of sediment loading Relying on dredging of deposited sediments on on floodplain basin (Ahilan, Guan, Sleigh, the bed of channels and culverts (Thorne, Wright, & Chang, 2018; Guan et al., 2018) 2014) Additional direct Water purification √ — environmental benefit Drought mitigation √ If water storage is designed in the system Reducing urban Heat √ — Island effect Habitat enhancement √ — policy to meet flood-related challenges lies in recognising elements with multifunctional BGI, that provides multiple the potential for specific flood risk management interven- cobenefits to a range of beneficiaries (Hoang et al., 2016). tions to take advantage of local climate, land-use, socio- For instance, introducing BGI (e.g., green roofs, bioswales, political, and governance conditions. deculverted urban streams) can not only reduce flood risk but In this context, this study examines historic urban flood also mitigate the urban heat island effect and the impacts of and water management practices in the city of Ningbo, to traffic noise, while improving water quality, providing access illustrate that sustainable urban water management has long to green spaces, uplifting neighbourhood aesthetics and been practiced and identify synergies that exist with the strengthening the community's sense of place (Lawson et al., “Blue-Green City” ideal of reconfiguring the urban water 2014; Stahre, 2008; Voskamp & Van de Ven, 2015). cycle to resemble the natural water cycle. Elements of the Table 1 presents a comparison of environmental benefits ancient surface water management system that align with the between the blue-green infrastructure (BGI) and grey infra- contemporary “Blue-Green City” concept, and those that structure. A Blue-Green City might not preserve natural fea- diverge from it, are discussed. The impacts of current urban tures present prior to urbanisation, and more commonly redevelopment and expansion in Ningbo on the ancient features engineered, green infrastructure that mimics nature. water management system are evaluated and it is argued that Furthermore, integrating grey infrastructure with Blue-Green urban flood and water management professionals could learn assets creates and optimises the multiple benefits of SuDS lessons from ancient practices, and should seek to incorpo- (Thorne, 2015). Widespread implementation of multibenefi- rate ancient infrastructure into modern systems by recognis- cial BGI in the United Kingdom (Ellis et al., 2016), United ing it as BGI capable of reducing flood risk while better States (BES, 2010), Europe (Stahre, 2008), Singapore (Tan enabling communities to “live with water”. These arguments et al., 2009), and Australia (Adams & Jayasuriya, 2014), are consistent with the Technical Guide for Constructing provides evidence of the potential advantages of adopting Sponge Cities (Ministry of Housing and Urban-Rural Devel- Blue-Green approaches in Chinese cities. opment of the People's Republic of China, 2014). Inclusion In 2013, the Chinese government declared its intention “ ” of Ningbo in the second round of the “Sponge City” cam- to convert Chinese cities into Sponge Cities : that is, cities paign, presents a great opportunity to rediscover and re- that (like a sponge) absorb excessive inputs of water from invent ancient “Blue-Green” strategies. excessive precipitation or river floods, retaining that water for use between input events and during prolonged dry periods. While this concept is simple in principle, the wide 1.2 | The Blue-Green concept and Sponge City variety of natural landscapes and hydro-climates in China initiatives proposed by the Chinese government requires diverse approaches to create “Sponge Cities” in A “Blue-Green City” aims to recreate a naturally oriented practice (Yin & Liu, 2015; Yu, 2015a). In 2015, the Chinese water cycle in an urban environment by integrating restored central government initially financed 16 “Sponge City” dis- and/or newly created water bodies with green infrastructure, tricts throughout the country as “pilot projects”, implement- to generate a range of environmental, economic, and social ing drainage systems featuring site-specific mixtures of rain- benefits (Hoyer et al., 2011; Novotny et al., 2010). Blue- gardens, urban meadows and wetlands, permeable pave- Green approaches aim to work with some of the single- ments, and bio-swales. A priori, the Sponge and Blue-Green purpose elements of the existing, grey infrastructure (such as City concepts fit together conformably (Lawson et al., 2014; flood embankments and pipes), while replacing other Novotny et al., 2010), particularly in regions where flood TANG ET AL. 3of14 risk and water security pose